Known is the machine for the flash-butt welding of rails (Patent of Ukraine No. 56986, of 16 Jun. 2003, Bull. No. 6), comprising two tong-type clamping devices, which are made in the form of two double-arm levers, mounted on a common central axle and isolated one from another, having a feasibility of moving along the axle one relative another, joined between themselves by means of two bimetal current-carrying rods of flashing-upsetting hydraulic cylinders, moreover, each of double-arm levers is hinge-connected by one end to a rod or casing of the hydraulic cylinder of clamping, respectively, and at the another end the clamping and current-carrying jaws are mounted, two welding transformers are built-in into hollow double-arm levers of one of two clamping devices joined by current-carrying jumpers through the current conductive parts of rods of flashing-upsetting hydraulic cylinders to current-carrying clamping jaws.
The closest prototype to the invention is the machine for the flash-butt welding of rails (Patent of Ukraine No. 101539, of 10 Apr. 2013, Bull. No 7), comprising a welding current power source, two tong-type clamping devices made in the form of double-arm levers mounted on a common central axle and isolated one from another, hydraulic cylinders of clamping and displacement of parts being welded.
The above-described machines for the flash butt welding of rails are similar by the design by that the tong-type clamping devices are joined between themselves by means of three rods, moreover, the rods of flashing-upsetting hydraulic cylinders are symmetrically arranged relative to a vertical plane of symmetry of rails and in parallel horizontal plane which is located below the web surface of the rails.
Such arrangement of the flashing-upsetting hydraulic cylinders is the main drawback of the above-described three-rod designs of welding machines-analogs, as this makes it impossible to apply them in welding of rails in hard-to-reach places, in particular, railway switches and frogs, the underground tracks, rails which are laid side by side at a close distance, etc.